As macOS becomes more prevalent in businesses, ensuring an application does not expose a user to vulnerabilities or your organization to business risk, is an important part of managing an organization’s risk. These apps often handle sensitive data, manage authentication and access system resources, making them attractive targets for cyber criminals to exploit. MacOS has unique security features that allow developers to build secure applications, but they must be correctly leveraged. Even with macOS's built-in security, vulnerabilities like insecure data storage, weak sandboxing and dynamic library hijacking can arise from misconfigurations and poor development practices.
By leveraging static and dynamic analysis, Kroll’s macOS Penetration Testing team can uncover these weaknesses and strengthen application defenses. Understanding these risks is the first step toward building resilient macOS applications that protect user data and maintain system integrity.
Common Vulnerabilities in macOS Native Applications
Insecure Data Storage
macOS apps frequently store sensitive information in Plist files, SQLite databases and Keychain entries—often unencrypted or with weak protection mechanisms.
- Example: Storing passwords in plaintext within Plist files (~/Library/Preferences/com.example.app.plist) can expose sensitive data to unauthorized users.
- Recommendation: Encrypt sensitive data before storage using AES encryption.
Insecure Network Communications
Some thick client apps disable App Transport Security (ATS) or fail to validate SSL certificates, leaving them vulnerable to Man-in-the-Middle (MitM) attacks.
- Example: An app transmitting data over plain HTTP can be intercepted, exposing sensitive information.
- Recommendation: Enforce ATS to ensure all network connections are secure and implement SSL pinning to prevent MitM attacks.
Sandboxing Misconfigurations & App Entitlement Exploits
Unlike iOS, where sandboxing is mandatory, macOS allows apps outside the Mac App Store to run without strict sandboxing.
Some applications request excessive entitlements, allowing them to access sensitive system resources beyond their intended scope.
- Example: A non-sandboxed app with Full Disk Access can read files from ~/Library/Containers/, exposing sensitive user data.
- Recommendation: Verify app entitlements and restrict unnecessary access.
Dynamic Library Injection & Code Execution Attacks
Attackers exploit Dylib Hijacking and Framework Injection to inject malicious code into legitimate applications.
- Example: A compromised dynamic library (.dylib) is placed in /usr/local/lib/, allowing an attacker to execute malicious code whenever a high-privilege app loads it.
- Recommendation: Enable Library Validation to prevent unauthorized dylib loading.
Reverse Engineering
Attackers can reverse engineer macOS thick client applications to extract hardcoded API keys, credentials, comments and even application logic, leading to unauthorized access and data leaks.
- Example: By decompiling the app binary using tools like Hopper or Ghidra, an attacker can locate hardcoded API keys within the executable or configuration files.
- Recommendation: Strip debugging symbols and use anti-tampering mechanisms to protect the binary.
macOS thick client applications, while powerful, present unique security challenges. Through proper implementation of security best practices and validation of security controls by experienced professionals, businesses can significantly reduce their risk exposure.
Investing in regular security audits, penetration testing and developer training will not only protect your data but also reinforce user trust. By addressing these vulnerabilities head-on, organizations can ensure their macOS applications are resilient against evolving threats.
To practice identifying and exploiting these vulnerabilities in a controlled environment, one can explore Damn Vulnerable macOS Application (DVMA), a custom-built macOS thick client application designed specifically for security professionals. This application allows hands-on experience with real-world macOS security flaws, making it an excellent learning resource.
